Protein kinase C (PKC) is a family of enzymes that play a crucial role in cellular signaling. They are involved in various processes, including cell growth, differentiation, and apoptosis (programmed cell death). PKC is activated by signals such as growth factors and hormones, which bind to cell surface receptors. Once activated, PKC phosphorylates specific target proteins, altering their function and activity. This phosphorylation process is essential for transmitting signals within the cell and regulating various physiological responses. Dysregulation of PKC activity has been linked to several diseases, including cancer and diabetes.